Fluid injection system

ABSTRACT

An injection system that eliminates the need for multiple syringe changes common to an angiographic or other catheterization procedure, is disclosed. The subject system includes a pair of reservoirs for respectively maintaining saline solution and contrast dye under pressure for controlled injection into a patient. The reservoirs are maintained full by automatically filled, after a predetermined time delay, whenever any amount is used. Peristaltic pumps connected to supplies of saline solution and contrast dye function to fill and refill the reservoirs.

United States Patent 1191 Rubinstein 1 1 FLUID INJECTION SYSTEM [76]Inventor: Morton K. Rubinstein, 3155 Antelo Rd., Los Angeles, Calif.90024 221 Filed: JuneZl, 1974 2| Appl. No.: 481,501

[52] US. Cl. 128/2 A; 128/214 F; 128/218 R; 128/218 G; 128/234 [51] Int.Cl A61b 6/00 [58] Field of Search... 128/2 A, 2 R, 2.05 D, 214 R,128/214 E, 214 F, 214 Z, 227, 229, 230, 218 R, 218 A, 218 G, 215,234-238 [56] References Cited UNITED STATES PATENTS 2,396,043 3/1946Evans 128/230 2,865,371 12/1958 Dorbecker et all 128/214 F 3,044.4657/1962 Anderson et a1. 128/230 3,313,291 4/1967 Marshall 128/2 A3,451,393 6/1969 Sarnoff 128/214 F June 10, 1975 OTHER PUBLICATIONSHector Brit. Jour. Radiology, 44, pp. 892-894, 1971 (Now),

Primary Examiner-Dalton L. Truluck Attorney, Agent, or Firm-Eric T. S.Chung [57] ABSTRACT An injection system that eliminates the need formultiple syringe changes common to an angiographic or othercatheterization procedure, is disclosed. The subject system includes apair of reservoirs for respectively maintaining saline solution andcontrast dye under pressure for controlled injection into a patient. Thereservoirs are maintained full by automatically filled, after apredetermined time delay, whenever any amount is used. Peristaltic pumpsconnected to supplies of saline solution and contrast dye function tofill and refill the reservoirs.

21 Claims, 4 Drawing Figures PATENTEDJUH 10 1975 SHEET Der.

25s. iwmcnroq Fl LL BSLe FLUID INJECTION SYSTEM BACKGROUND OF THEINVENTION 1. Field of the Invention This invention generally relates tomedical equipment useful in performing an angiographic or othercatheterization procedure. More specifically, the present inventionconcerns a fluid injection system that is designed for use in carryingout an angiographic procedure or other catheterization.

2. Description of the Prior Art Recent advances in medical science haveincluded the development and refinement of diagnostic Xray techniques.Angiography or arteriography is one of such diagnostic X-ray techniques.

Generally, angiography involves the injection of radio-opaque dye orcontrast dye into an artery or arteries of a human body underexamination. When X-rays are thereafter taken, a shadow is produced bythe dye on the X-ray pictures and thereby provides an outline of thearteries in which the dye has been injected. The shadow is due to theX-rays passing through the normal body tissues but not the dye.

Angiography thus allows physicians and other medical diagnosticians tostudy almost any part of the body as well as the blood vessels andspecific organs in a human body. As an example, injection ofradio-opaque dye into blood vessels will indicate the presence ofobstructions, blockages, or constriction of the arteries. Alsoidentifiable would be displacement of the arteries. Such information isessential in completely studying patients to determine the presence orabsence of brain tumors, blood clots, and other abnormalities, and theneed for corrective surgery or the like. As a further example,angiography is useful for examining patients that may be suffering fromheart disease to determine the existence of blocked or partiallyobstructed coronary arteries as may be present in connection with anangina condition or following a heart attack.

Contrast dye can also be injected directly into the heart to determinethe existence of leaky valves. The basic angiographic procedure is alsoadapted for use in obtaining pressure measurements as is useful indiagnosing leaky heart valves.

Typically, an angiographic procedure involves directly inserting acatheter into one of the blood vessels of the body. The major artery inthe groin is frequently chosen, although other arteries may also beused. A needle may be first inserted into the artery and a catheter thenthreaded through the hollow of the needle into the artery. The needlecan then be removed. Once inserted into the artery, the catheter is thenslowly threaded through the artery to have the tip thereof becomesituated in the area of the body or within the organ to be examined.

It is necessary that the location of the catheter be known at all times.To this end, small amounts of contrast dye are introduced at frequentintervals through the catheter to have the dye fill the blood vessel atthe tip of the catheter. A fluoroscope may then be used to provide aspecific indication of the whereabouts of the tip of the catheter withinthe body as it is threaded into the body through the artery.

Dye and saline cannot be left in the catheter for too long a period oftime because of the possibility of clot formation. Accordingly, thecatheter must be intermittently rinsed with fresh saline solution whichis injected through the catheter into the body to wash the dye out ofthe catheter.

Injection of the dye and saline solutions is presently accomplished bythe use of syringes which are alternately manually connected anddisconnected from the end of the catheter or extensions thereof. Hence,each injection of contrast dye requires that two separate syringes besuccessively attached and detached from the catheter. In the course of asingle angiographic procedure to study parts of a patiens head or neck,as many as 50 or more syringe changes may be required.

The withdrawal of blood through the catheter, as may be required duringan angiographic procedure, would require further attachment anddetachment of a syringe or syringes from the catheter.

Culmination of the angiographic procedure occurs when the catheter isfinally worked into the position desired, and a relatively large volumeof contrast dye is quickly injected under high pressure into the area tobe examined. A plurality of X-ray pictures are then taken in quicksuccession. As an example, study of the heart normally involvesinjection of 40 cc of dye at a pressure of 1,000 psi. Examination of thebrain would typically involve the injection of 8 cc of contrast dyeunder a pressure of 40 psi. If the X-ray pictures that are taken aresatisfactory, the catheter is either removed or relocated to anotherregion of the body for study.

Other forms of catheterization would include hystosalpingograms,retrograde cysternograms and cardiac catheterizations. In each instance,a catheter is inserted into a blood vessel or other body cavity for thepurpose of injecting fluid into the cavity, taking pressuremeasurements, and/or withdrawing blood or other body fluids.

It is clear that the current techniques for performing an angiographicprocedure are crude, time consuming, and dangerous, however usefuland/or necessary the results may be. Specifically, the need for numeroussyringe connections and disconnections as dye and saline solution isinjected is tedious as well as time consuming; but perhaps of mostimportance is the danger presented by the opportunity for clot formationas a result of exposure to air in the course of the many syringechanges.

Accordingly, it is an intension of the subject invention to provide afluid injection system that completely eliminates any exposure to air inthe course of an angiographic procedure and is highly sanitary, whicheliminates the need for the multiple syringe connections anddisconnections to the catheter, and which permits a physician or otherperson to safely and quickly perform angiographic procedures.

SUMMARY OF THE INVENTION Briefly described, the present inventioninvolves a fluid injection system for use in the performance of anangiographic or other catheterization procedure.

More specifically, the subject invention involves a closed fluid systemthat eliminates the need for the numerous syringe changes that arepresently required in the course of an angiographic procedure and whichthereby eliminates exposure to air and the attendant dangers resultingfrom the formation of clots. The system includes a pair of independent,pressurized reservoirs which are respectively continuously filled, aftera nominal time delay, with contrast dye and saline solution wheneverfluid is drawn from a reservoir. Pumping mechanisms connected tosupplies of such fluids are automatically actuated to refill therespective reser voirs. Means are included for providing an indicationof both total consumption of the fluids as well as the size of each dosethat is injected. A vacuum pump is used to maintain a waste container ata negative pressure with respect to body pressure to enable theextraction of fluid from a patients body.

The objects and many attendant advantages of the invention will be morereadily appreciated as the same becomes better understood by referenceto the follow ing description which is to be considered in connectionwith the accompanying drawings wherein like reference symbols designatelike parts throughout the figures thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagramillustrating a perspective view of the subject invention.

FIG. 2 is a schematic diagram illustrating a partially cut away,frontal, plan view of a console used in conjunction with an angiographicinjection system in accordance with the subject invention.

FIG. 3 is a schematic diagram illustrating a partially cut away, side,plan view of the console shown in FIG. 2.

FIG. 4 is a schematic diagram illustrating an electrical circuit that isuseful in understanding the operation of the subject invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of thedrawings, an angiographic injection system in accordance with thepresent invention includes a console unit 2 connected to a supply ofcontrast dye 4 via tubing 6 and a supply of saline solution 8 via tubing10. The console 2 is connected to continuously make available andprovide the contrast dye and the saline solution to a catheter 12 upondemand via a manually operable valve control 14 and a pair of outputtubes 16 and 18, respectively. The console unit 2 is also connected viaa vacuum hose 20 to depressurize or reduce the pressure of a wastecontainer 22.

It is to be understood that although contrast dye is discussed hereinthat any radio-opaque medium suitable for use in an angiographicprocedure can be used with the subject invention.

As earlier explained, an angiographic or other catheterization procedurerequires the catheter 12 to be threaded into a patients body via anappropriate artery or other blood vessel. Contrast dye and salinesolution is injected through the catheter 12 at frequent intervals tocontinuously locate and observe the position of the tip thereof. Hence,the manually operated valve control 14 includes a pair of valveactuators 24 and 26, each of which functions to open and close a valveto control the flow of dye and saline solution to the catheter 12 viathe console 2. As an example, the valve actuators 24 and 26 may simplybe levers which control a three port fluid valve which is effectivelyopened or closed by turning of the valve actuators 24 and 26 to permitor stop the flow of fluid to or from the catheter l2. Accordingly, eachof the actuators 24 and 26 may have a forward position for permittingthe injection of fluid through the catheter l2, and a backward positionfor extracting a fluid through the catheter 12, and a middle position inwhich no flow is permitted. Any of the nume rous types of conventionalfluid valves that are available in the prior art may be employed as thevalve control 14 and the valve actuators 24 and 26 thereof. Extractedfluid may be directed through a hose 27 to the waste container 22.

Referring to FIGS. 2 and 3, the console 2 includes a pair of identicalindependent pressurized reservoir systerns respectively for the contrastdye provided from the supply 4 and for the saline solution provided fromthe supply 8. A first reservoir 28 may be used for the contrast dye anda second reservoir 30 may be used for saline solution by beingrespectively connected to have fluid supplied thereto from the supplies4 and 8 by a pair of peristaltic pumps 32 and 34 through the tubes 6 and10. Fluid in the reservoirs 28 and 30 are maintained under pressure by apair of spring assemblies 36 and 38, respectively.

Considered in greater detail, the reservoirs 28 and 30 may eachessentially take the form of a syringe and accordingly include acylindrical housing 40, an inletoutlet needle 42, and a plunger 44. Thecapacity of each of the reservoirs may be in the neighborhood of 20-40cc; but any other appropriate capacity may be used. As is well known,retraction of the plunger 44 from within the housing 40 will cause fluidto be drawn into the interior cavity of the housing 40. Similarly,forcing fluid into the housing 40 through the needle 42 will causeejection of the plunger 44. Conversely, insertion of the plunger 44 intothe cavity of the housing 40 will force fluid contained therein to beejected through the needle 42.

An appropriate walled mount 45 may be used to removably support andretain syringes that are emplaced as reservoirs 28 and 30. As shown, themount 45 may simply involve a clip-like fixture that receives thehousing 40 therein and thereby holds the housing 40 stationary. Themounting fixture 45 may, of course, have any other configuration thatwould allow insertion and removal of the syringes that are emplaced asreservoirs in accordance with the subject invention.

It is to be understood that although a syringe is described for use asreservoirs 28 and 30, other configurations or similar devices may bealso employed.

Referring to the saline reservoir 30, as an example, fluid is forcedinto the reservoir 30 by operation of a peristaltic pump 34 which servesto draw saline solution from the supply 8 via the tubing 10. As shown,the tubing 10 is wound through the pump 34 and is connected to thereservoir 30 via a suitable fluid T-joint 46. The output tubing 18 isalso connected to an arm of the T-joint 46. Operation of the pump 34will cause saline solution to be pumped through the T-joint 46 into thereservoir 30 provided that the output tubing 18 is closed off such asthe valve actuator 26. In the event that the output tubing 18 is openedsuch as by operation of the valve actuator 26, the pump 34 will functionto pump fluid through the output tubing 18 and through the catheter 12assuming that a stop-cock 48, which may be provided, as shown in FIG. 1,is opened rather than closed.

The spring assembly 38 operates to maintain fluid contained by thereservoir 30 under pressure by having a telescopic section 50 thereofpositioned against the end of the plunger 44 to urge said plunger 44into the housing 40 to thereby eject the fluid therein. The amount offorce or pressure applied to the plunger 44 by the telescoping section50 of the spring assembly 38 may be readily adjusted by operation of anadjustment knob 52 which extends through an outer casing 54 of theconsole 2. The adjustment knob 52 is threadably connected to a springcompression plate 56 which functions to compress a spring 58 as it isdriven in a downward position in FIG. 2 in response to appropriateturning of the knob 52. Increased compression of the springs 58 will, ofcourse, increase the force applied to the plunger 44 via the telescopingsection 50 and thereby increase the pressure of the fluid contained bythe reservoir 30. The spring assembly 38 may be readily calibrated in amanner well known to persons skilled in the art to obtain desired fluidpressures for the contrast dye and saline solution that are providedfrom the reservoirs 28 and 30 and as may be required for the examinationof different organs, i.e., 40 psi for injection of contrast dye into abrain being examined.

The telescoping section 50 may be equipped with an indicator arrow 60 orthe like which extends through a slot 62 in the casing 54 to provide avisual indication. in conjunction with a scale 64, of the size of eachdose of fluid ejected or injected into a patient. To this end, refillinga reservoir after the ejection of each dose is nominally delayed, i.e.,5 seconds, to permit a true un interrupted dose indication, as isexplained hereinbelow.

The indicator arrow 60 would be in a raised position when the reservoiris filled and would be lowered as the plunger 44 is driven into thehousing 40 by the spring assembly 38 as fluid is ejected. The scale 64may involve any appropriate units such as cubic centimeters (cc) and maybe simply painted or etched onto the cas ing 54. The indicating arrow 60may also be mechanically connected to trigger an audible indicatingdevice as predetermined amounts of fluid are ejected. For example, areed comb-type of device could be used to sound a tone as the indicatorarrow 60 is lowered past individual reeds.

A window 65 may also be provided to allow visual observation of thecontents of each reservoir.

An indication of total consumption of saline solution may be desired andbe provided by an indicator 66 which is connected by a drive belt 68 tobe driven in conjunction with operation of the peristaltic pump 34. Anarmature assembly 69 on the pump 34 may be conveniently used for thispurpose. Operation of the pump 34 would cause the belt 68 tosimultaneously drive the indicator 66 in a conventional fashion. Theindicator 66 may be in the form of an odometer-like device or any otherconventional indicator device well known in the prior art. A similarindicator would be connected to the pump 32 to indicate totalconsumption of contrast dye.

As a safety measure, the output tubes 16 and 18 may be connected to bemonitored by a bubble detector 70 of a type well known in the art. Forexample, a bubble indicator 70 may simply involve a photoelectric cellwhich would be positioned to produce an output signal wheneverillumination directed thereon were to vary, such as by being increasedin response to the passage of an air bubble 70. The bubble detector 70would be connected to de-energize the system such as by automaticallyopening a switch or the like, as is explained hereinafter in greaterdetail.

A vacuum pump 72 may be contained within the casing 54 and haveconnected thereto the vacuum hose of which one end is placed in theclosed waste container 22 to reduce the pressure therein, Depressurizingthe container 22 to a pressure that is lower than body pressurefunctions to facilitate withdrawal of fluid from a patients body. Avacuum gauge 73 may be mounted on the casing 54 of the console 2.

Refilling of the reservoirs 28 and 30 after the withdrawal of any fluidtherefrom is automatically accomplished by having the pumps 32 and 34respectively connected to be automatically operated whenever thereservoir is not full. Any convenient switching arrangement can be usedsuch as by having a wiper arm shown in FIG. 3 serve as a portion of anelectrical switch that is closed whenever the plunger 44 of thereservoir is at any position other than at a maximum raised positionsuch as is shown for the plunger 44 of the reservoir 30 in FIG. 2. Suchelectrical switch may simply involve a contact strip (not shown) thatcontacts the wiper arm 71 when the plunger 44 is lowered. Clearly thewiper arm 71 can be appropriately secured to the indicator arrow 60 orto the telescoping section 50 (as shown) or even to the plunger 44,although such connection would be less desirable.

Clearly, the subject fluid injection system is a closed fluid system andhence substantially eliminates the possibility of air bubbles beingintroduced into the subject. Further, the subject system is highlysanitary in that all portions of the system that are exposed to or comein contact with the saline solution and contrast dye are disposable andreadily replaceable. Specifically, the disposable items would includethe supply bottles 4 and 8, tubes 6 and 10, reservoirs 28 and 30,T-joints 46, tubes 16 and 18, and finally valve control l4. The catheter12 is normally an expensive item and hence is sterilized for reuse.

Referring to FIG. 4, an electrical circuit for each of the peristalticpumps 32 and 34 may include a plug 74 which is adapted to be connectedto any conventional AC power source. Using the pump 34 as an example,the electrical circuit may include a series connected main power switch76 which may be in the form of a push button switch, or a toggle switch,etc., a safety fuse 76, a refill switch 80, a delay timer 82, and a bubble detector switch 84. The refill switch 80 would be closed in responseto the reservoir 30 not being filled as above discussed and would beopened whenever the reservoir 30 is filled.

The delay timer 82 would serve to delay energization of the pump 34 andhence delay the filling of the reservoir 30 to permit the dose indicator60 to provide an accurate indication before the corresponding pumpcommences to refill the reservoir. Any conventional time delay devicemay be used to produce the desired nominal time delay, i.e., four to sixseconds, following each withdrawal of fluid before operation of thepumps 32 and 34. The time delay is chosen to accommodate the time neededto complete an injection. The bubble detector switch 84 would normallybe closed; but would be automatically opened in response to detection ofan air bubble by the detector 70.

It is to be understood that the pumps 32 and 34 may be effectivelyconnected in parallel in a single circuit or in separate circuitssimilar to that illustrated by FIG. 4.

The vacuum pump 72 may also be connected to have an electrical circuitsimilar to that shown by FIG. 4 or be connected to a common power bussalong with the pumps 32 and 34. However, there would be no need for anytime delay as the vacuum pump 72 may be continuously operated.

From the foregoing it is now clear that the subject invention presents afluid injection system that permits contrast dye and saline solution tobe readily supplied to and injected through a catheter without the needfor the numerous connections and disconnections that must be manuallyaccomplished in accordance with present techniques and which therebyeliminates or substantially reduces the danger of clot formationresulting from exposure to air, extensive time consumption, and anydiscomfort that may be attendant to the conventional need for suchsyringe changes.

While a preferred embodiment of the present invention has been describedhereinabove, it is intended that all matter contained in the abovedescription and shown in the accompanying drawings be interpreted asillustrative and not in a limiting sense and that all modifications,constructions and arrangements which fall within the scope and spirit ofthe invention may be made.

What is claimed is:

1. An angio-graphic injection system for continuously providing to acatheter supplies of two separate fluids used in the performance of acatheterization procedure, the injection system comprising:

a pair of reservoir means for containing a ready supply of said twofluids, respectively;

a pair of pressurizing means each connected to one of said pair ofreservoir means for maintaining said fluids contained therein under apredetermined pressure;

a pair of pumping means respectively connected to one of said reservoirmeans for pumping fluid into said reservoir means from a source thereofto continuously maintain said reservoir means in a filled condition;

and fluid conduit means for interconnecting said respective reservoirmeans and pump means, said fluid conduit means provided with means forbeing connected to a catheter to supply said fluids thereto.

2. The injection system defined by claim 1, further including a pair ofpump actuating means each connected to be respectively responsive to adifferent one of said reservoir means being in an unfilled condition forcausing a pumping means to be energized to pump fluid to said reservoirmeans until obtaining a filled condition.

3. The injection system defined by claim 2, said pump actuating meansincluding time delay means for delaying energization of said pumpingmeans by a predetermined period of time following said reservoir meanshaving an unfilled condition.

4. The injection system defined by claim 1, further including vacuummeans adapted to be connected to a container for receiving waste fluidsfor reducing the interior pressure of said container.

5. The injection system defined by claim 1, further including valvecontrol means connected to said pair of reservoir means for controllingthe withdrawal of said fluids from both said reservoir means.

6. The injection system defined by claim 1, said pair of reservoir meanseach including:

a housing defining an interior cavity;

a plunger adapted to be inserted into and retracted from said interiorcavity; and

inlet means extending through said housing into said cavity whereby saidfluid is injected into and ejected from said interior cavity throughsaid inlet means.

7. The injection system defined by claim 1, said pair of reservoir meanseach including a syringe having an inlet needle thereof connected tohave fluid ejected therethrough and pumped therethrough by said pumpingmeans.

8. The injection system defined by claim 1, said pair of pumping meanseach including a peristaltic pump.

9. The injection system defined by claim 1, said pair of pressurizingmeans each including spring biased means for applying a mechanical forceto said reservoir means corresponding thereto to have fluid contained bysaid reservoir means maintained at a predetermined pressure in saidreservoir.

10. The injection system defined by claim 9, said spring biased meansincluding:

a telescoping member;

a spring positioned to apply a mechanical force to said telescopingmember; and means for adjustably compressing said spring to adjust saidmechanical force applied to said telescoping member in accordance withsaid determined pressure.

11. The injection system defined by claim 2, each of said pump actuatingmeans including:

switching means responsive to a corresponding one of said reservoirmeans being in an unfilled condition for causing electrical energy to beapplied to a corresponding one of said pumping means; and

time delay means connected to said switching means for delayingenergization of said pumping means by a predetermined period of timefollowing said reservoir means having an unfilled condition.

12. The injection system defined by claim 6, said pair of pressurizingmeans each including spring biased means for applying a force to saidplunger at a corresponding one of said reservoir means to have fluidcontained in said interior cavity maintained at a predeterminedpressure.

13. The injection system defined by claim 12, said spring biased meansincluding:

a telescoping member;

a spring positioned to apply a mechanical force to said telescopingmember; and

means for adjustably compressing said spring to adjust said mechanicalforce applied to said telescoping member in accordance with saiddetermined pressure.

14. The injection system defined by claim 13, further including a pairof pump actuating means each connected to be respectively responsive toa different one of said reservoir means being in an unfilled conditionfor causing a pumping means to be energized to pump fluid to saidreservoir means until obtaining a filled condition.

15. The injection system defined by claim 14, each of said pumpactuating means including:

switching means responsive to a corresponding one of said reservoirmeans being in an unfilled condition for causing electrical energy to beapplied to a corresponding one of said pumping means; and

time delay means connected to said switching means for delayingenergization of said pumping means by a predetermined period of timefollowing said reservoir means having an unfilled condition.

of the volume of each dose of fluid ejected from said reservoir means.said indicator means being positioned to respond to movement of saidplunger of said reservoir means.

20. The injection system defined by claim 6, further including mountingmeans for removably securing each of said reservoir means whereby saidreservoir means are each adapted to be removable and disposable.

21. The injection system defined by claim 18, said two fluids includingsaline solution and radio-opaque dyes.

1. An angio-graphic injection system for continuously providing to acatheter supplies of two separate fluids used in the performance of acatheterization procedure, the injection system comprising: a pair ofreservoir means for containing a ready supply of said two fluids,respectively; a pair of pressurizing means each connected to one of saidpair of reservoir means for maintaining said fluids contained thereinunder a predetermined pressure; a pair of pumping means respectivelyconnected to one of said reservoir means for pumping fluid into saidreservoir means from a source thereof to continuously maintain saidreservoir means in a filled condition; and fluid conduit means forinterconnecting said respective reservoir means and pump means, saidfluid conduit means provided with means for being connected to acatheter to supply said fluids thereto.
 2. The injection system definedby claim 1, further including a pair of pump actuating means eachconnected to be respectively responsive to a different one of saidreservoir means being in an unfilled condition for causing a pumpingmeans to be energized to pump fluid to said reservoir means untilobtaining a filled condition.
 3. The injection system defined by cLaim2, said pump actuating means including time delay means for delayingenergization of said pumping means by a predetermined period of timefollowing said reservoir means having an unfilled condition.
 4. Theinjection system defined by claim 1, further including vacuum meansadapted to be connected to a container for receiving waste fluids forreducing the interior pressure of said container.
 5. The injectionsystem defined by claim 1, further including valve control meansconnected to said pair of reservoir means for controlling the withdrawalof said fluids from both said reservoir means.
 6. The injection systemdefined by claim 1, said pair of reservoir means each including: ahousing defining an interior cavity; a plunger adapted to be insertedinto and retracted from said interior cavity; and inlet means extendingthrough said housing into said cavity whereby said fluid is injectedinto and ejected from said interior cavity through said inlet means. 7.The injection system defined by claim 1, said pair of reservoir meanseach including a syringe having an inlet needle thereof connected tohave fluid ejected therethrough and pumped therethrough by said pumpingmeans.
 8. The injection system defined by claim 1, said pair of pumpingmeans each including a peristaltic pump.
 9. The injection system definedby claim 1, said pair of pressurizing means each including spring biasedmeans for applying a mechanical force to said reservoir meanscorresponding thereto to have fluid contained by said reservoir meansmaintained at a predetermined pressure in said reservoir.
 10. Theinjection system defined by claim 9, said spring biased means including:a telescoping member; a spring positioned to apply a mechanical force tosaid telescoping member; and means for adjustably compressing saidspring to adjust said mechanical force applied to said telescopingmember in accordance with said determined pressure.
 11. The injectionsystem defined by claim 2, each of said pump actuating means including:switching means responsive to a corresponding one of said reservoirmeans being in an unfilled condition for causing electrical energy to beapplied to a corresponding one of said pumping means; and time delaymeans connected to said switching means for delaying energization ofsaid pumping means by a predetermined period of time following saidreservoir means having an unfilled condition.
 12. The injection systemdefined by claim 6, said pair of pressurizing means each includingspring biased means for applying a force to said plunger at acorresponding one of said reservoir means to have fluid contained insaid interior cavity maintained at a predetermined pressure.
 13. Theinjection system defined by claim 12, said spring biased meansincluding: a telescoping member; a spring positioned to apply amechanical force to said telescoping member; and means for adjustablycompressing said spring to adjust said mechanical force applied to saidtelescoping member in accordance with said determined pressure.
 14. Theinjection system defined by claim 13, further including a pair of pumpactuating means each connected to be respectively responsive to adifferent one of said reservoir means being in an unfilled condition forcausing a pumping means to be energized to pump fluid to said reservoirmeans until obtaining a filled condition.
 15. The injection systemdefined by claim 14, each of said pump actuating means including:switching means responsive to a corresponding one of said reservoirmeans being in an unfilled condition for causing electrical energy to beapplied to a corresponding one of said pumping means; and time delaymeans connected to said switching means for delaying energization ofsaid pumping means by a predetermined period of time following saidreservoir means having an unfilled condition.
 16. The injection systemdefined by claim 15, further including valve control meAns connected tosaid pair of reservoir means for controlling the withdrawal of saidfluids from both said reservoir means.
 17. The injection system definedby claim 16, further including vacuum means adapted to be connected to acontainer for receiving waste fluids for reducing the interior pressureof said container.
 18. The injection system defined by claim 17, saidpair of pumping means each including a peristaltic pump.
 19. Theinjection system defined by claim 6 further including indicator meansfor providing an indication of the volume of each dose of fluid ejectedfrom said reservoir means, said indicator means being positioned torespond to movement of said plunger of said reservoir means.
 20. Theinjection system defined by claim 6, further including mounting meansfor removably securing each of said reservoir means whereby saidreservoir means are each adapted to be removable and disposable.
 21. Theinjection system defined by claim 18, said two fluids including salinesolution and radio-opaque dyes.